Evaluation of ink-jet printed current collecting grids and bushbars for ITO-free organic solar cells

ITO-free organic solar cells with ink-jet printed current collecting grids and high conducting PEDOT:PSS as a composite anode are demonstrated. Inkjet printed current collecting grids with different cross-sectional areas have been investigated. The effect of the width and height of the grid lines and busbars has been measured and modeled by direct current (DC) simulations. The electrical potential in devices with different grid profiles have been calculated and reveal critical bottlenecks in the grid electrode geometry, as the ability of the busbar to collect all the current. Experimentally, the upper limit of the conductivity of the ink-jet printed current collecting grids is limited by the topology of the grids and shadow losses in the solar cells.